You're already there. When you booted ONE you cloned the glance image to a cinder device (A', separate RBD) that was a COW clone of A. That's why
you can't delete A until you flatten SNAP1. A' isn't a full copy until that flatten is complete, at which point you're able to delete A.
SNAP2 is a second snapshot on A', and thus A' already has all of the data it needs from the previous flatten of SNAP1 to allow you to delete SNAP1. So SNAP2 isn't actually a full extra copy of the data.
SNAP2 is a second snapshot on A', and thus A' already has all of the data it needs from the previous flatten of SNAP1 to allow you to delete SNAP1. So SNAP2 isn't actually a full extra copy of the data.
 |
Steve Taylor |
Senior Software Engineer |
StorageCraft
Technology Corporation 380 Data Drive Suite 300 | Draper | Utah | 84020 Office: 801.871.2799 |
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-----Original Message-----
From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf Of Eugen Block
Sent: Thursday, September 1, 2016 6:51 AM
To: ceph-users@xxxxxxxxxxxxxx
Subject: Turn snapshot of a flattened snapshot into regular image
Hi all,
I'm trying to understand the idea behind rbd images and their clones/snapshots. I have tried this scenario:
1. upload image A to glance
2. boot instance ONE from image A
3. make changes to instance ONE (install new package) 4. create snapshot SNAP1 from ONE 5. delete instance ONE 6. delete image A
deleting image A fails because of existing snapshot SNAP1 7. flatten snapshot SNAP1 8. delete image A
succeeds
9. launch instance TWO from SNAP1
10. make changes to TWO (install package) 11. create snapshot SNAP2 from TWO 12. delete TWO 13. delete SNAP1
succeeds
This means that the second snapshot has the same (full) size as the first. Can I manipulate SNAP1 somehow so that snapshots are not flattened anymore and SNAP2 becomes a cow clone of SNAP1?
I hope my description is not too confusing. The idea behind this question is, if I have one base image and want to adjust that image from time to time, I don't want to keep several versions of that image, I just want one. But this way i would lose the protection from deleting the base image.
Is there any config option in ceph or Openstack or anything else I can do to "un-flatten" an image? I would assume that there is some kind of flag set for that image. Maybe someone can point me to the right direction.
Thanks,
Eugen
--
Eugen Block voice : +49-40-559 51 75
NDE Netzdesign und -entwicklung AG fax : +49-40-559 51 77
Postfach 61 03 15
D-22423 Hamburg e-mail : eblock@xxxxxx
Vorsitzende des Aufsichtsrates: Angelika Mozdzen
Sitz und Registergericht: Hamburg, HRB 90934
Vorstand: Jens-U. Mozdzen
USt-IdNr. DE 814 013 983
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf Of Eugen Block
Sent: Thursday, September 1, 2016 6:51 AM
To: ceph-users@xxxxxxxxxxxxxx
Subject: Turn snapshot of a flattened snapshot into regular image
Hi all,
I'm trying to understand the idea behind rbd images and their clones/snapshots. I have tried this scenario:
1. upload image A to glance
2. boot instance ONE from image A
3. make changes to instance ONE (install new package) 4. create snapshot SNAP1 from ONE 5. delete instance ONE 6. delete image A
deleting image A fails because of existing snapshot SNAP1 7. flatten snapshot SNAP1 8. delete image A
succeeds
9. launch instance TWO from SNAP1
10. make changes to TWO (install package) 11. create snapshot SNAP2 from TWO 12. delete TWO 13. delete SNAP1
succeeds
This means that the second snapshot has the same (full) size as the first. Can I manipulate SNAP1 somehow so that snapshots are not flattened anymore and SNAP2 becomes a cow clone of SNAP1?
I hope my description is not too confusing. The idea behind this question is, if I have one base image and want to adjust that image from time to time, I don't want to keep several versions of that image, I just want one. But this way i would lose the protection from deleting the base image.
Is there any config option in ceph or Openstack or anything else I can do to "un-flatten" an image? I would assume that there is some kind of flag set for that image. Maybe someone can point me to the right direction.
Thanks,
Eugen
--
Eugen Block voice : +49-40-559 51 75
NDE Netzdesign und -entwicklung AG fax : +49-40-559 51 77
Postfach 61 03 15
D-22423 Hamburg e-mail : eblock@xxxxxx
Vorsitzende des Aufsichtsrates: Angelika Mozdzen
Sitz und Registergericht: Hamburg, HRB 90934
Vorstand: Jens-U. Mozdzen
USt-IdNr. DE 814 013 983
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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